The invention described and claimed herein relates generally to processes and apparatus for aligning two portions having generally flat alignment surfaces and then preventing further lateral movement thereof. The invention relates specifically to apparatus and method describing an adjustable support member for providing support to certain portions of a rotatable shaft in the opening and closing mechanism of a circuit interrupter or switch assembly. The invention also specifically relates to apparatus and method for positioning bushings and pole pieces of a circuit interrupter during assembly to provide accurate alignment thereof with a complementary stationary contact.
It is known in the prior art to utilize method and apparatus for affixing certain portions of bolts and their corresponding nuts with flat planar surfaces to prevent certain kinds of motion. As an example, the common lock washer, such as shown in U.S. Pat. No. 1,786,502, issued Dec. 30, 1930 to H. G. Norwood is utilized to provide springlike compression between a nut on a bolt and a flat surface through which the bolt protrudes. The axial pressure provided by the spring-compression of the lock washer as the nut is tightened upon it has a tendency to lock the nut in place relative to the flat surface. Another lock washer device is generally known as the star shaped lock washer. This washer is provided between a flat surface and a nut to prevent the nut from rotating once it has been tightened onto the star shaped lock washer. The star shaped lock washer generally has radial protruding portions which provide pressure against the nut and the flat surface, or in some cases actually dig into the nut and/or the flat surface to prevent the rotational motion of the nut about its bolt. It is also known in the prior art to provide adjustable link members. Two examples are shown in U.S. Pat. No. 566,323 issued Aug. 25, 1896 to J. J. Kelleher and H. Irwin and U.S. Pat. No. 1,652,677 issued Dec. 13, 1927 to W. F. McCoy et al. Both of the previously described patents utilize the concept of pre-cut matching incremental indexed grooves which allow for adjustment in small increments between parts of the linkage. The manufacturer of switch gear equipment, such as circuit breakers and switch assemblies, requires in many cases utilization of adjustable portions to provide alignment, but which thereafter can be securely positioned to prevent further movement of one portion of the link relation to the other. As an example, in the past it has been the practice to mount an insulated bushing having a steel channel at the bottom thereof into a support member at the base of a circuit breaker apparatus. The bushing is positioned in the previously described base apparatus so that a knife blade or pole piece on another portion of the bushing may be aligned with a separate contact for the subsequent making and breaking of a circuit. In the past, the adjustment was accomplished by first making a proper alignment and then simultaneously drilling matching holes in the complementary channel and the base support which holds and accommodates a bolt. The bolt is generally utilized in conjunction with a nut to tighten the two pieces in the aligned position to prevent further relative lateral movement. Also, certain shaft mechanisms of a circuit breaker that are movable into and out of engagement with each other, must be supported at outboard portions thereof or flexing of the shaft, rather than rotation thereof, may occur as magnetic and electrical forces interact with the closed contact. It would be advantageous therefore to provide means for supplementary supporting the latter mentioned shaft so that flexure of the shaft would be minimized. It would also be advantageous to provide an apparatus and method for securing the bottom member of the previously described insulated bushing to the previously described base member which apparatus and method did not require drilling after alignment. The cost involved in drilling after alignment is significantly larger than the cost of providing pre-punched members. However pre-punched members provide a disadvantage in the fact that if the pre-punched holes are the same diameter as the bolt which adjoins one member to another, then flexibility in adjustment has been reduced. However, if the hole is sufficiently large to provide flexibility of adjustment, then the opportunity for undesired movement into nonalignment of one part relative to the other after adjustment is increased. It would be advantageous therefore to provide means for adjusting the relative position of two flat surfaces with respect to each other and also to provide a securely affixed arrangement of the two parts relative to each other after desired alignment has been made.